A conventional telescopic centerpost of a multiple-fold umbrella as shown in FIGS. 1 and 2 comprises an arcuate spring plate A having an upper catch C supporting a slider or runner S of umbrella spokes or ribs R of an umbrella canopy or cloth, and a plurality of cylindrical tubes telescopically connected with one another. However, such a conventional telescopic centerpost may have the following drawbacks:
1. In order for retractably receiving all the telescopic tubes T1, T2 and T3 into the slider S, the cylindrical hole S1 of the slider S should be made as large as possible and the flange S3 is formed with an arcuate opening S2 for smoothly folding the telescopic tubes, the catch C of the spring plate A may be easily poked into the hole S1 without supporting the flange S3 of the slider S, thereby causing an accidental collapsing action of an open umbrella.
2. Since the arcuate plate A is limited by a coupling catch C1 formed on its lower portion so that the total length of the plate A is quite limited to possibly reduce its resilience as easily causing an elastic fatigue of the spring plate, thereby influencing a folding or extending operation of the umbrella.
3. The upper catch C of the spring plate A is provided for resting the slider S thereon. Upon a depression of the catch C when retracting the umbrella ribs R for closing the umbrella, the outer acute angle of the catch C may easily injure an umbrella user.
4. The round or cylindrical handle tube T4 of the centerpost T may be easily slipped and can not be gripped firmly due to its round surface.
The present inventor has found the drawbacks of a conventional telescopic centerpost and invented the present antislipping telescopic centerpost of a multiple-fold umbrella.